Understanding the dynamics of surface water area and their drivers is crucial for human survival and ecosystem stability in inland arid and semi-arid areas.This study took Gansu Province,China,a typical area with comp...Understanding the dynamics of surface water area and their drivers is crucial for human survival and ecosystem stability in inland arid and semi-arid areas.This study took Gansu Province,China,a typical area with complex terrain and variable climate,as the research subject.Based on Google Earth Engine,we used Landsat data and the Open-surface Water Detection Method with Enhanced Impurity Control method to monitor the spatiotemporal dynamics of surface water area in Gansu Province from 1985 to 2022,and quantitatively analyzed the main causes of regional differences in surface water area.The findings revealed that surface water area in Gansu Province expanded by 406.88 km2 from 1985 to 2022.Seasonal surface water area exhibited significant fluctuations,while permanent surface water area showed a steady increase.Notably,terrestrial water storage exhibited a trend of first decreasing and then increasing,correlated with the dynamics of surface water area.Climate change and human activities jointly affected surface hydrological processes,with the impact of climate change being slightly higher than that of human activities.Spatially,climate change affected the'source'of surface water to a greater extent,while human activities tended to affect the'destination'of surface water.Challenges of surface water resources faced by inland arid and semi-arid areas like Gansu Province are multifaceted.Therefore,we summarized the surface hydrology patterns typical in inland arid and semi-arid areas and tailored surface water'supply-demand'balance strategies.The study not only sheds light on the dynamics of surface water area in Gansu Province,but also offers valuable insights for ecological protection and surface water resource management in inland arid and semi-arid areas facing water scarcity.展开更多
As a national policy of benefiting the country and the people, " precision" poverty alleviation has an important strategic position.The core of " precision" poverty alleviation is education poverty...As a national policy of benefiting the country and the people, " precision" poverty alleviation has an important strategic position.The core of " precision" poverty alleviation is education poverty alleviation. Based on the background of " precision" poverty alleviation,this study focuses on the analysis of problems of rural inclusive private kindergartens in the province,such as the shortage of rural pre-school resources,the uneven quality of teachers,and lack of financial investment. And in view of the existing problems,this paper puts forward some solutions to better promote the rural inclusive kindergarten development in the province.展开更多
Using Geography Information System (GIS) tools and remote sensing data in assessing the level of vulnerability of agricultural production activities in the coastal area has become more efficient in the recent years. T...Using Geography Information System (GIS) tools and remote sensing data in assessing the level of vulnerability of agricultural production activities in the coastal area has become more efficient in the recent years. This research has identified the sensitivity index (S) (including the traffic access index;the impact of residential areas;the impacts of industrial zones;the community dependence level), exposure index (E) (the sea level rises to 2100;the temperature change to 2100), the adaptable capacity index (AC) (slope;morphology), thereby synthesizing the vulnerability index (V). Based on the indexes to calculate vulnerability, the high to very high vulnerability area is 37,081.44 ha, accounting for 68.09%;the average vulnerability level is 15,286.49 ha, accounting for 28.07%;the low to very low vulnerability level with an area is 2087.82 ha, accounting for 3.84% of the total area. With a high and very high vulnerability accounting for 68.09%, there will be great influences on the lives of resident in the area, especially agricultural production.展开更多
Large amounts of sediments originating from the Changjiang(Yangtze)River are deposited in the subaqueous delta and in the adjacent muddy area off the mouth and on the inner shelf of the East China Sea.The terrestrial ...Large amounts of sediments originating from the Changjiang(Yangtze)River are deposited in the subaqueous delta and in the adjacent muddy area off the mouth and on the inner shelf of the East China Sea.The terrestrial sediments deposited in these areas not only contain information about the composition and environment of the source area,but they also record changes in anthropogenic activities.A sediment piston core(CJ0702)was extracted from the Changjiang subaqueous depocenter(31.00°N,122.67°E)in a water depth of 22.0 m.The core was subsampled at 1–2 cm intervals and analyzed for grain size,clay mineralogy,and major element geochemistry.Results indicate a relatively high sediment accumulation rate of approximately 3.11 cm yr−1.These parameters exhibited only minor cyclical fluctuations in the core,which resulted from many factors.During the past 120 years,the Changjiang River-derived sediment is the primary source of sediment in the offshore mud area without evidence for the Yellow River-derived sediment increasing.After the trunk stream shifted from the North Branch to South Branch,the variations of proxies are controlled by the periodic fluctuation possibly linked to El Niño-Southern Oscillation(ENSO)and the Pacific Decadal Oscillation(PDO).In addition,anthropogenic heavy metal concentrations can be divided into three stages,which coincide well with economic development and environmental protection policies.展开更多
Natural conditions in Bashang area are characterized by zonal transitions which are liable to be impacted by natural disasters and intensified human activities. The extremely fragile eco-environment is also liable to ...Natural conditions in Bashang area are characterized by zonal transitions which are liable to be impacted by natural disasters and intensified human activities. The extremely fragile eco-environment is also liable to have desertification formed and developed. In the 18 years from 1978 to 1996, the desertified land area of Bashang within the scope of the map nearly doubled, a total increase of 2199.11 km2, averaging an increase of 122.17 km2 per year. Moreover, the seriously desertified area increases rapidly. Land desertification in Bashang is the combined result of natural factors and irrational human economic activities. Cultivated land expansion, population growth, and overgrazing aggrevate desertification development.展开更多
Long-term changes of composition, sources and burial fluxes of TOC （total organic carbon） in sediments of the central Yellow Sea mud area and their possible affecting factors are discussed in this paper. Firstly, si...Long-term changes of composition, sources and burial fluxes of TOC （total organic carbon） in sediments of the central Yellow Sea mud area and their possible affecting factors are discussed in this paper. Firstly, similarity analysis is employed to confirm that the carbon burial features resulted from two collected cores are typical in the central Yellow Sea mud area where YSWC （Yellow Sea Warm Current） is prevalent. On this basis, the burial flux of TOC here was considered to be 235.5-488.4 pmol/（cm^2.a） since the first industrial revolution, accounting for about 70%-90% among burial fluxes of TC （total carbon） in the sediments. Compared TOC/TC ratio in the two cores with that in other marine sediments worldwide, we suggest that the growth of calcareous/non-calcareous organisms and dissolution of IC （inorganic carbon） are important factors controlling the TOC/TC ratio in sediment. Results of two-end mixed model based on fi13C data indicate that marine-derived organic carbon （OCa） is the main part among total burial organic carbon which accounts for a ratio over 85%. Due to the high TOC/TC ratio in the two cores, TC in the sediments also mainly exists as OCa, and the proportion of OCa is about 60%-80%. Away from the shore and relatively high primary production in upper waters are the main reasons that OCa is predominant among all burial OC in sediments of the central Yellow Sea mud area. Burial of OC in this mud area is probably mainly influenced by the human activities. Although the economic development during the late 19th century caused by the first industrial revolution in China did not obviously increase the TOC burial fluxes in the sediments, the rise of industry and agriculture after the founding of new China has clearly increased the TOC burial flux since 1950s. Otherwise, we also realize that among TC burial fluxes, TIC account for about 10%-30% in sediments of the central Yellow Sea mud area, so its burial could not be simply ignored here. Distinct from TOC burial, long-term TIC burial fluxes variations relate with climate changes more closely： the East Asian summer monsoon may influence the strength of the Huanghe River （Yellow River） flood, which could further affect the transport of terrestrial IC from land to the central Yellow Sea as well as the burial of these IC in the sediments.展开更多
Obvious tendency and periodicity of the air temperature can be detected over the North Pole area.They are reflected as follows： a.the air temperature at the earth surface and in the middle layer of the stratosphere t...Obvious tendency and periodicity of the air temperature can be detected over the North Pole area.They are reflected as follows： a.the air temperature at the earth surface and in the middle layer of the stratosphere tends to be increased either in winter or in summer.The air temperature has increased 1.3 °C for about 50 years at a speed about 0.025 °C/year in January,and 0.013 °C/year in July.The air temperature in the middle layer of the stratosphere （10 hPa） in January has increased 10 °C.The temperature rising speed in July is 0.14 °C/year.Generally speaking,the temperature rising speed is quicker in winter than in summer and quicker in the upper layer than at the earth surface.b.The air temperature at the top layer of the troposphere （100 hPa） over the North Pole area tends to be increased either in winter or in summer.The air temperature in January has decreased 5.0 °C for about 50 years at a temperature decreasing speed about 0.094 °C/year,and at a temperature decreasing speed about 0.032 °C/year in July.The speed of the temperature decreasing is greater in winter than in summer.c.Periodicity.The air temperature respectively at different altitudes over the North Pole possesses interdecadal variation with a period of 22 years.In July the amplitude of the variation with a period of 22 years decreases rapidly from the high altitude to the low.This means that the 22–year’s period is more obvious at the high altitude than at the low altitude.At the earth surface layer in North Pole there also is obvious decadal variation with a period of 11 years.The analysis indicates that the 22-years’ period temperature variation is associated with the periodic variation of the solar magnetic field.The 11-year period temperature variation is corresponding to 11 year’ period of the variation of the sunspot number.展开更多
In this paper,thermosphere density data of"SZ-2"Atmospheric Density Detec tor From February to April 2001 are used to study the changes of the thermo sphere density in the sunshine and shaded area during sol...In this paper,thermosphere density data of"SZ-2"Atmospheric Density Detec tor From February to April 2001 are used to study the changes of the thermo sphere density in the sunshine and shaded area during solar and geomagnetic activity.The results show that in the sunshine area,the peak value of atmo spheric density changes as F10.7 varies;during geomagnetic activity,the peak value of atmospheric density in the shaded area increases as Ap increases,and start off with higher latitude,therefore move to lower latitude.展开更多
Coastal zone is the complex area with intense sea-land interaction. There are various types, complex environments and developed economy in coastal area of China. Under the influence of global change and human activiti...Coastal zone is the complex area with intense sea-land interaction. There are various types, complex environments and developed economy in coastal area of China. Under the influence of global change and human activities, the ecosystem of coastal zone is vulnerable and has sensitive response to environment changes. The environmental problems of sea-level rising have attached close attention by countries all over the world. As far as regions concerned, relative sea-level rising is more important than theoretical sea-level rising. The relative sea-level rising has resulted in series of environment disasters in coastal area of China, such as coastal erosion, seawater invasion, and floods in coastal lowlands, etc. The flux of sediments transported by rivers into sea is the main material source of marine pollution. The human activities are controlling factors of variations in river sediment loads. Under the influence of high strength development in the upstream region, the results are that the reduction of seagoing sediments in main rivers of China, and damage of coastal material balance. Land-based pollution is the main source of marine pollution. With rapid economic development in China s eastern coastal, pollutants flux into sea increase gradually. The results are that the environmental quality and seawater quality of marine have being deteriorated and pollution is serious increasingly. To meet the land demand of industrialization and urbanization, the sea reclamation has become an effective means to alleviate the contradiction between human and land in coastal area of China. This leads to large-scale reduction of coastal wetland area, and the heavy losses of ecological service value of coastal wetland. To face the environmental changes in coastal area of China and solve the contradiction among population, resources, environment, development, it is required to set up the system concept of man-land-sea relationship, so as to achieve sustainable development. The feasible measures include improving coastal management system, strengthening integrated basin management, attaching importance to construction of the coastal environment engineering, and raising the environmental monitoring and early warning level.展开更多
An activated carbon with ash content less than 10% and specific surface area more than 1 600 m 2 /g was prepared from coal and the effect of K containing compounds in preparation of coal based activated carbon was inv...An activated carbon with ash content less than 10% and specific surface area more than 1 600 m 2 /g was prepared from coal and the effect of K containing compounds in preparation of coal based activated carbon was investigated in detail in this paper. KOH was used in co carbonization with coal, changes in graphitic crystallites in chars derived from carbonization of coal with and without KOH were analyzed by X ray diffraction (XRD) technique, activation rates of chars with different contents of K containing compounds were deduced, and resulting activated carbons were characterized by nitrogen adsorption isotherms at 77 K and iodine numbers. The results showed that the addition of KOH to the coal before carbonization can realize the intensive removal of inorganic matters from chars under mild conditions, especially the efficient removal of dispersive quartz, an extremely difficult separated mineral component in other processes else. Apart from this, KOH demonstrates a favorable effect in control over coal carbonization with the goal to form nongraphitizable isotropic carbon precursor, which is a necessary prerequisite for the formation and development of micro pores. However, the K containing compounds such as K 2 CO 3 and K 2 O remaining in chars after carbonization catalyze the reaction between carbon and steam in activation, which leads to the formation of macro pores. In the end an innovative method, in which KOH is added to coal before carbonization and K containing compounds are removed by acid washing after carbonization, was proposed for the synthesis of quality coal based activated carbon.展开更多
More than 500 datasets from the literature have been used to evaluate the relationships of specific surface area (SSA),cation exchange capacity (CEC) and activity versus the liquid limit (LL).The correlations gave R^2...More than 500 datasets from the literature have been used to evaluate the relationships of specific surface area (SSA),cation exchange capacity (CEC) and activity versus the liquid limit (LL).The correlations gave R^2 values ranging between 0.71 and 0.92.Independent data were also used to validate the correlations.Estimated SSA values slightly overestimate the measured SSA up to 100 m^2/g.Regarding the estimated CEC values,they overestimated the measured CEC values up to 20 meq/(100 g).A probabilistic approach was performed for the correlations of SSA,CEC and activity versus LL.The analysis shows that the relations of SSA,CEC and activity with LL are robust.Using the LL values,it is possible to assess other basic engineering properties of clays.展开更多
We apply three methods to relocate 599 earthquake events that occurred from August 2004 to August 2005 in the northeastern Tianshan Mountains area ( 85°30' ～ 88°30'E,43°00' ～ 44°40...We apply three methods to relocate 599 earthquake events that occurred from August 2004 to August 2005 in the northeastern Tianshan Mountains area ( 85°30' ～ 88°30'E,43°00' ～ 44°40' N ) by using travel times recorded by regional seismic network and 10 portable seismic stations deployed around the Urumqi city. By comparing the reliability of different results,we determined a suitable location method,and an improved 1-D crustal velocity model of the study area. The uncertainty of earthquake location is significantly reduced with combined data of seismic network and portable stations. The relocated events are clearly associated with regional tectonics of the northeastern Tianshan Mountains area, and are also in agreement with the existence of active faults imaged by deep seismic reflection profile. The relocated seismicity discovers some potential traces of buried active faults,which need to be validated further.展开更多
Using neutron activation analysis method we determined contents of rare-earth and radioactive elements (La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, Cs, Rb, Sb, Sc, Sr, Ba, U, Th) in source water system of the Changjiang (Yangtze)...Using neutron activation analysis method we determined contents of rare-earth and radioactive elements (La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, Cs, Rb, Sb, Sc, Sr, Ba, U, Th) in source water system of the Changjiang (Yangtze) River, which is mainly composed of the Tuotuo River, the Chumaer River, and the Buqu River. The contents of these elements in the unflltered water have a great variation and a close correlation with the water turbidity. The contents of these elements in filtered water only have a little variation and are lower than those in the unflltered water. The variations in contents of these elements in sediments are also very little. These elements in the unifiltered water are in geometric distribution, except Sc. Most of the elements in sediments are in arithmetic distribution, but Cs, Sb, Th, are in deviation distribution. The contents of most of these elements in the river source area correspond to the contents of fresh water of the earth. Most of these elements have a little variation in their展开更多
In this work, ZnO nanorod arrays grown by an electrochemical deposition method are investigated. The crucial parameters of length, diameter, and density of the nanorods are optimized over the synthesize process and na...In this work, ZnO nanorod arrays grown by an electrochemical deposition method are investigated. The crucial parameters of length, diameter, and density of the nanorods are optimized over the synthesize process and nanorods growth time. Crystalline structure, morphologies, and optical properties of ZnO nanorod arrays are studied by different techniques such as x-ray diffraction, scanning electron microscope, atomic force microscope, and UV-visible transmission spectra. The ZnO nanorod arrays are employed in an inverted bulk heterojunction organic solar cell of Poly （3-hexylthiophene）：[6- 6] Phenyl-（6） butyric acid methyl ester to introduce more surface contact between the electron transporter layer and the active layer. Our results show that the deposition time is a very important factor to achieve the aligned and uniform ZnO nanorods with suitable surface density which is required for effective infiltration of active area into the ZnO nanorod spacing and make a maximum interfacial surface contact for electron collection, as overgrowing causes nanorods to be too dense and thick and results in high resistance and lower visible light transmittance. By optimizing the thickness of the active layer on top of ZnO nanorods, an improved efficiency of 3.17% with a high FF beyond 60% was achieved.展开更多
By shallow seismic prospecting, it is showed that the faults in the sea area near the Yangtze River mouth are mainly the NE and NW-trending faults. The main activity time of fault is Pliocene to Early Pleistocene, and...By shallow seismic prospecting, it is showed that the faults in the sea area near the Yangtze River mouth are mainly the NE and NW-trending faults. The main activity time of fault is Pliocene to Early Pleistocene, and the latest activity is up to Middle Pleistocene. The maximum of fault is generally several tens meters with the throw decreased upward. The dislocation near the bottom of Middle Pleistocene is 12~13 m. The average vertical dis-placement rate is on a level of 10-3 mm/a.展开更多
In order to clear the activated area in electrostatic accelerator facilities,four accelerator facilities were selected and typical neutron emission experiments were performed.Neutron flux during operation and induced ...In order to clear the activated area in electrostatic accelerator facilities,four accelerator facilities were selected and typical neutron emission experiments were performed.Neutron flux during operation and induced activity caused by charged particles on the accelerator and its surrounding area after irradiation were measured.Also the monitored neutron flux and calculated value by Monte Carlo calculation using PHITS code were compared.It was confirmed that the results between calculated data and measured data showed the good agreement with each other.Finally,it was concluded that we have to take care the activation of beam line and target.But,it is not necessary to treat accelerator tank,surrounding materials,and building concrete as radioactive materials in case of decommissioning.展开更多
Microbiological and physical\|chemical characteristics of subtropical forest, grassland and cropfield soils from the karst areas of Southwest China were investigated. The study revealed that the conversion of natural ...Microbiological and physical\|chemical characteristics of subtropical forest, grassland and cropfield soils from the karst areas of Southwest China were investigated. The study revealed that the conversion of natural forest to other forms of land would lead to a reduction in soil organic C(26.2%-35.3%), total N(37.2%-55.8%), total P(32.9%-43.6%), microbial biomass C(35.4%-49.1%), N(37.2%-55.8%), and P(25.8%-41.9%). Comparative analysis of microbial activity in terms of basal soil respiration showed maximum activity in forest soil and minimum in cropfield soil. Analysis of microbial metabolic respiratory activity indicated a relatively greater respiratory loss of CO\-2—C per unit microbial biomass in cropfield and grassland than in forest soil. Considering the importance of microbial components in soil, it is concluded that land use in different ways will lead to the reduction of biological stability of soil.展开更多
In Burkina Faso, human activities are practiced in Nazinga Game Ranch (NGR) which is colonized by West African crocodiles Crocodylus suchus (Geoffroy Saint-Hilaire 1807) decades ago. This study which aims to estimate ...In Burkina Faso, human activities are practiced in Nazinga Game Ranch (NGR) which is colonized by West African crocodiles Crocodylus suchus (Geoffroy Saint-Hilaire 1807) decades ago. This study which aims to estimate impact of anthropogenic activities on abundance of C. suchus has been conducted in NGR reservoirs. For data collection, C. suchus populations were counted morning, afternoon and night from October 2015 to May 2017 in 11 reservoirs. Binoculars were used for remote observations and spotlight was used by night. According to the size of the sites and its accessibility, direct observations were carried out on foot or by canoe. Every time we observed crocodiles, they were numbered and added information such as their size, their behavior, geographical coordinates and the type of habitat were collected. Human activities were noted after direct observations. The R software version 3.5.3 was used for data analysis. A total of 1849 crocodiles including hatchlings, juveniles, subadults and adults were counted in these 11 reservoirs of the NGR. They were more abundant in reservoirs than rivers with highest abundances in Akalon, Akwazena, Kalieboulou and Barka. Crocodile showed very high visibility at night their abundances showed important correlation with human activities and environmental factors such as roads, fishing, tourism, moon phases and “died crocodiles” and in NGR.展开更多
The main purpose of this study is to identify the socio-economic implications of re-current flooding on women development in southern Ijaw Local Government Area. Generally, flooding may result in socio-economic, ecolo...The main purpose of this study is to identify the socio-economic implications of re-current flooding on women development in southern Ijaw Local Government Area. Generally, flooding may result in socio-economic, ecological and health problems. This study assumes that on flood days the movement of customers and sellers tends to be hindered, thus resulting in the retardation of transactions and the reduction of daily income earned. The study compared the situation of female traders with that of male traders. Both primary and secondary data were used in this study. Primary data were collected using an open-ended questionnaire. A total of 83 questionnaires were randomly distributed to members of four communities, which were selected through stratified random sampling procedures. Also 33 randomly selected women and men respectively, engaged in marketing activities from open and locked-up shops, were sampled to observe the level of their personal income (in Naira), from customers patronage during 3 flood days and 3 non-flood days. Other data and information were obtained through Key Informants Interview (KII), and observations. Hypotheses I and II were tested using Analysis of Variance (ANOVA) statistical model. Null hypothesis I (H<sub>0</sub>), which states that “There is no statistically significant difference in the income earned by men and women traders from marketing activities on flood days and non-flood days in Southern Ijaw Local Government Area, Bayelsa State”, is accepted (F-value: 3.8723939, P-value: 2.494E-05), whereas null hypothesis II (H<sub>0</sub>), which states that “There is no statistically significant difference in the income earned by women traders from marketing activities on flood and non-flood days in Southern Ijaw Local Government Area, Bayelsa State, is rejected (F-value: 2.524902, P-value: 0.030069). Thus while there is no significant difference in the earnings of male and female traders on flood and non-flood days, there are significant differences in sales earning among women traders on those days. Factors affecting trading income on flood and non-flood days include accessibility to business premises by customers, ability of male marketers to afford non-easily flooded business premises;and women traders with limited resources often have less suitably drained premises. Reduced total household income can detrimentally affect food affordability, availability, household nutrition, family health and wellbeing. Recommendations highlighting the roles of communities, government and stakeholders in flood management are proffered.展开更多
Large amounts of gas hydrate are distributed in the northern slope of the South China Sea,which is a potential threat of methane leakage.Aerobic methane oxidation by methanotrophs,significant methane biotransformation...Large amounts of gas hydrate are distributed in the northern slope of the South China Sea,which is a potential threat of methane leakage.Aerobic methane oxidation by methanotrophs,significant methane biotransformation that occurs in sediment surface and water column,can effectively reduce atmospheric emission of hydrate-decomposed methane.To identify active aerobic methanotrophs and their methane oxidation potential in sediments from the Shenhu Area in the South China Sea,multi-day enrichment incubations were conducted in this study.The results show that the methane oxidation rates in the studied sediments were 2.03‒2.36μmol/gdw/d,which were higher than those obtained by sediment incubations from other areas in marine ecosystems.Thus the authors suspect that the methane oxidation potential of methanotrophs was relatively higher in sediments from the Shenhu Area.After the incubations family Methylococcaea(type I methanotrophs)mainly consisted of genus Methylobacter and Methylococcaea_Other were predominant with an increased proportion of 70.3%,whereas Methylocaldum decreased simultaneously in the incubated sediments.Collectively,this study may help to gain a better understanding of the methane biotransformation in the Shenhu Area.展开更多
基金This research was supported by the Third Xinjiang Scientific Expedition Program(2021xjkk010102)the National Natural Science Foundation of China(41261047,41761043)+1 种基金the Science and Technology Plan of Gansu Province,China(20YF3FA042)the Youth Teacher Scientific Capability Promoting Project of Northwest Normal University,Gansu Province,China(NWNU-LKQN-17-7).
文摘Understanding the dynamics of surface water area and their drivers is crucial for human survival and ecosystem stability in inland arid and semi-arid areas.This study took Gansu Province,China,a typical area with complex terrain and variable climate,as the research subject.Based on Google Earth Engine,we used Landsat data and the Open-surface Water Detection Method with Enhanced Impurity Control method to monitor the spatiotemporal dynamics of surface water area in Gansu Province from 1985 to 2022,and quantitatively analyzed the main causes of regional differences in surface water area.The findings revealed that surface water area in Gansu Province expanded by 406.88 km2 from 1985 to 2022.Seasonal surface water area exhibited significant fluctuations,while permanent surface water area showed a steady increase.Notably,terrestrial water storage exhibited a trend of first decreasing and then increasing,correlated with the dynamics of surface water area.Climate change and human activities jointly affected surface hydrological processes,with the impact of climate change being slightly higher than that of human activities.Spatially,climate change affected the'source'of surface water to a greater extent,while human activities tended to affect the'destination'of surface water.Challenges of surface water resources faced by inland arid and semi-arid areas like Gansu Province are multifaceted.Therefore,we summarized the surface hydrology patterns typical in inland arid and semi-arid areas and tailored surface water'supply-demand'balance strategies.The study not only sheds light on the dynamics of surface water area in Gansu Province,but also offers valuable insights for ecological protection and surface water resource management in inland arid and semi-arid areas facing water scarcity.
基金Supported by the Key Humanities and Social Sciences Project of the 13th FiveYear Plan in Hebei Province(1602079)
文摘As a national policy of benefiting the country and the people, " precision" poverty alleviation has an important strategic position.The core of " precision" poverty alleviation is education poverty alleviation. Based on the background of " precision" poverty alleviation,this study focuses on the analysis of problems of rural inclusive private kindergartens in the province,such as the shortage of rural pre-school resources,the uneven quality of teachers,and lack of financial investment. And in view of the existing problems,this paper puts forward some solutions to better promote the rural inclusive kindergarten development in the province.
文摘Using Geography Information System (GIS) tools and remote sensing data in assessing the level of vulnerability of agricultural production activities in the coastal area has become more efficient in the recent years. This research has identified the sensitivity index (S) (including the traffic access index;the impact of residential areas;the impacts of industrial zones;the community dependence level), exposure index (E) (the sea level rises to 2100;the temperature change to 2100), the adaptable capacity index (AC) (slope;morphology), thereby synthesizing the vulnerability index (V). Based on the indexes to calculate vulnerability, the high to very high vulnerability area is 37,081.44 ha, accounting for 68.09%;the average vulnerability level is 15,286.49 ha, accounting for 28.07%;the low to very low vulnerability level with an area is 2087.82 ha, accounting for 3.84% of the total area. With a high and very high vulnerability accounting for 68.09%, there will be great influences on the lives of resident in the area, especially agricultural production.
基金the National Natural Science Foundation of China(Nos.41676052 and 41206073)the State Scholarship Fund sponsored by China Scholarship Council(No.201609370007)the China Geological Survey(Nos.DD20190236,DD20160137,and DD20190205).
文摘Large amounts of sediments originating from the Changjiang(Yangtze)River are deposited in the subaqueous delta and in the adjacent muddy area off the mouth and on the inner shelf of the East China Sea.The terrestrial sediments deposited in these areas not only contain information about the composition and environment of the source area,but they also record changes in anthropogenic activities.A sediment piston core(CJ0702)was extracted from the Changjiang subaqueous depocenter(31.00°N,122.67°E)in a water depth of 22.0 m.The core was subsampled at 1–2 cm intervals and analyzed for grain size,clay mineralogy,and major element geochemistry.Results indicate a relatively high sediment accumulation rate of approximately 3.11 cm yr−1.These parameters exhibited only minor cyclical fluctuations in the core,which resulted from many factors.During the past 120 years,the Changjiang River-derived sediment is the primary source of sediment in the offshore mud area without evidence for the Yellow River-derived sediment increasing.After the trunk stream shifted from the North Branch to South Branch,the variations of proxies are controlled by the periodic fluctuation possibly linked to El Niño-Southern Oscillation(ENSO)and the Pacific Decadal Oscillation(PDO).In addition,anthropogenic heavy metal concentrations can be divided into three stages,which coincide well with economic development and environmental protection policies.
基金National Natural Science Foundation of China No. 49894170
文摘Natural conditions in Bashang area are characterized by zonal transitions which are liable to be impacted by natural disasters and intensified human activities. The extremely fragile eco-environment is also liable to have desertification formed and developed. In the 18 years from 1978 to 1996, the desertified land area of Bashang within the scope of the map nearly doubled, a total increase of 2199.11 km2, averaging an increase of 122.17 km2 per year. Moreover, the seriously desertified area increases rapidly. Land desertification in Bashang is the combined result of natural factors and irrational human economic activities. Cultivated land expansion, population growth, and overgrazing aggrevate desertification development.
基金The National Key Basic Research Program of China under contract No.2010CB428902the United Program of National Natural Science Foundation of China and Shandong Province under contract No.U1406403the Special Fund for Basic Scientific Research Business of Central Public Research Institutes under contrast No.20603022013003
文摘Long-term changes of composition, sources and burial fluxes of TOC （total organic carbon） in sediments of the central Yellow Sea mud area and their possible affecting factors are discussed in this paper. Firstly, similarity analysis is employed to confirm that the carbon burial features resulted from two collected cores are typical in the central Yellow Sea mud area where YSWC （Yellow Sea Warm Current） is prevalent. On this basis, the burial flux of TOC here was considered to be 235.5-488.4 pmol/（cm^2.a） since the first industrial revolution, accounting for about 70%-90% among burial fluxes of TC （total carbon） in the sediments. Compared TOC/TC ratio in the two cores with that in other marine sediments worldwide, we suggest that the growth of calcareous/non-calcareous organisms and dissolution of IC （inorganic carbon） are important factors controlling the TOC/TC ratio in sediment. Results of two-end mixed model based on fi13C data indicate that marine-derived organic carbon （OCa） is the main part among total burial organic carbon which accounts for a ratio over 85%. Due to the high TOC/TC ratio in the two cores, TC in the sediments also mainly exists as OCa, and the proportion of OCa is about 60%-80%. Away from the shore and relatively high primary production in upper waters are the main reasons that OCa is predominant among all burial OC in sediments of the central Yellow Sea mud area. Burial of OC in this mud area is probably mainly influenced by the human activities. Although the economic development during the late 19th century caused by the first industrial revolution in China did not obviously increase the TOC burial fluxes in the sediments, the rise of industry and agriculture after the founding of new China has clearly increased the TOC burial flux since 1950s. Otherwise, we also realize that among TC burial fluxes, TIC account for about 10%-30% in sediments of the central Yellow Sea mud area, so its burial could not be simply ignored here. Distinct from TOC burial, long-term TIC burial fluxes variations relate with climate changes more closely： the East Asian summer monsoon may influence the strength of the Huanghe River （Yellow River） flood, which could further affect the transport of terrestrial IC from land to the central Yellow Sea as well as the burial of these IC in the sediments.
基金The Global Change Research Program of China under contract No. 2010CB951403the National Natural Science Foundations of China under contract No. 40875041
文摘Obvious tendency and periodicity of the air temperature can be detected over the North Pole area.They are reflected as follows： a.the air temperature at the earth surface and in the middle layer of the stratosphere tends to be increased either in winter or in summer.The air temperature has increased 1.3 °C for about 50 years at a speed about 0.025 °C/year in January,and 0.013 °C/year in July.The air temperature in the middle layer of the stratosphere （10 hPa） in January has increased 10 °C.The temperature rising speed in July is 0.14 °C/year.Generally speaking,the temperature rising speed is quicker in winter than in summer and quicker in the upper layer than at the earth surface.b.The air temperature at the top layer of the troposphere （100 hPa） over the North Pole area tends to be increased either in winter or in summer.The air temperature in January has decreased 5.0 °C for about 50 years at a temperature decreasing speed about 0.094 °C/year,and at a temperature decreasing speed about 0.032 °C/year in July.The speed of the temperature decreasing is greater in winter than in summer.c.Periodicity.The air temperature respectively at different altitudes over the North Pole possesses interdecadal variation with a period of 22 years.In July the amplitude of the variation with a period of 22 years decreases rapidly from the high altitude to the low.This means that the 22–year’s period is more obvious at the high altitude than at the low altitude.At the earth surface layer in North Pole there also is obvious decadal variation with a period of 11 years.The analysis indicates that the 22-years’ period temperature variation is associated with the periodic variation of the solar magnetic field.The 11-year period temperature variation is corresponding to 11 year’ period of the variation of the sunspot number.
文摘In this paper,thermosphere density data of"SZ-2"Atmospheric Density Detec tor From February to April 2001 are used to study the changes of the thermo sphere density in the sunshine and shaded area during solar and geomagnetic activity.The results show that in the sunshine area,the peak value of atmo spheric density changes as F10.7 varies;during geomagnetic activity,the peak value of atmospheric density in the shaded area increases as Ap increases,and start off with higher latitude,therefore move to lower latitude.
基金Supported by National Natural Science Foundation of China(Grant No.:41501003,41701101 41807403)Open Foundation of Research Institute of Jiangsu Coastal Development(Grant No.:RIJCD11008)
文摘Coastal zone is the complex area with intense sea-land interaction. There are various types, complex environments and developed economy in coastal area of China. Under the influence of global change and human activities, the ecosystem of coastal zone is vulnerable and has sensitive response to environment changes. The environmental problems of sea-level rising have attached close attention by countries all over the world. As far as regions concerned, relative sea-level rising is more important than theoretical sea-level rising. The relative sea-level rising has resulted in series of environment disasters in coastal area of China, such as coastal erosion, seawater invasion, and floods in coastal lowlands, etc. The flux of sediments transported by rivers into sea is the main material source of marine pollution. The human activities are controlling factors of variations in river sediment loads. Under the influence of high strength development in the upstream region, the results are that the reduction of seagoing sediments in main rivers of China, and damage of coastal material balance. Land-based pollution is the main source of marine pollution. With rapid economic development in China s eastern coastal, pollutants flux into sea increase gradually. The results are that the environmental quality and seawater quality of marine have being deteriorated and pollution is serious increasingly. To meet the land demand of industrialization and urbanization, the sea reclamation has become an effective means to alleviate the contradiction between human and land in coastal area of China. This leads to large-scale reduction of coastal wetland area, and the heavy losses of ecological service value of coastal wetland. To face the environmental changes in coastal area of China and solve the contradiction among population, resources, environment, development, it is required to set up the system concept of man-land-sea relationship, so as to achieve sustainable development. The feasible measures include improving coastal management system, strengthening integrated basin management, attaching importance to construction of the coastal environment engineering, and raising the environmental monitoring and early warning level.
文摘An activated carbon with ash content less than 10% and specific surface area more than 1 600 m 2 /g was prepared from coal and the effect of K containing compounds in preparation of coal based activated carbon was investigated in detail in this paper. KOH was used in co carbonization with coal, changes in graphitic crystallites in chars derived from carbonization of coal with and without KOH were analyzed by X ray diffraction (XRD) technique, activation rates of chars with different contents of K containing compounds were deduced, and resulting activated carbons were characterized by nitrogen adsorption isotherms at 77 K and iodine numbers. The results showed that the addition of KOH to the coal before carbonization can realize the intensive removal of inorganic matters from chars under mild conditions, especially the efficient removal of dispersive quartz, an extremely difficult separated mineral component in other processes else. Apart from this, KOH demonstrates a favorable effect in control over coal carbonization with the goal to form nongraphitizable isotropic carbon precursor, which is a necessary prerequisite for the formation and development of micro pores. However, the K containing compounds such as K 2 CO 3 and K 2 O remaining in chars after carbonization catalyze the reaction between carbon and steam in activation, which leads to the formation of macro pores. In the end an innovative method, in which KOH is added to coal before carbonization and K containing compounds are removed by acid washing after carbonization, was proposed for the synthesis of quality coal based activated carbon.
文摘More than 500 datasets from the literature have been used to evaluate the relationships of specific surface area (SSA),cation exchange capacity (CEC) and activity versus the liquid limit (LL).The correlations gave R^2 values ranging between 0.71 and 0.92.Independent data were also used to validate the correlations.Estimated SSA values slightly overestimate the measured SSA up to 100 m^2/g.Regarding the estimated CEC values,they overestimated the measured CEC values up to 20 meq/(100 g).A probabilistic approach was performed for the correlations of SSA,CEC and activity versus LL.The analysis shows that the relations of SSA,CEC and activity with LL are robust.Using the LL values,it is possible to assess other basic engineering properties of clays.
基金supported by the Basic Research Project of Institute of Earthquake Science,CEA (2012IES010103)the National Natural Science Foundation of China (41204037)
文摘We apply three methods to relocate 599 earthquake events that occurred from August 2004 to August 2005 in the northeastern Tianshan Mountains area ( 85°30' ～ 88°30'E,43°00' ～ 44°40' N ) by using travel times recorded by regional seismic network and 10 portable seismic stations deployed around the Urumqi city. By comparing the reliability of different results,we determined a suitable location method,and an improved 1-D crustal velocity model of the study area. The uncertainty of earthquake location is significantly reduced with combined data of seismic network and portable stations. The relocated events are clearly associated with regional tectonics of the northeastern Tianshan Mountains area, and are also in agreement with the existence of active faults imaged by deep seismic reflection profile. The relocated seismicity discovers some potential traces of buried active faults,which need to be validated further.
文摘Using neutron activation analysis method we determined contents of rare-earth and radioactive elements (La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, Cs, Rb, Sb, Sc, Sr, Ba, U, Th) in source water system of the Changjiang (Yangtze) River, which is mainly composed of the Tuotuo River, the Chumaer River, and the Buqu River. The contents of these elements in the unflltered water have a great variation and a close correlation with the water turbidity. The contents of these elements in filtered water only have a little variation and are lower than those in the unflltered water. The variations in contents of these elements in sediments are also very little. These elements in the unifiltered water are in geometric distribution, except Sc. Most of the elements in sediments are in arithmetic distribution, but Cs, Sb, Th, are in deviation distribution. The contents of most of these elements in the river source area correspond to the contents of fresh water of the earth. Most of these elements have a little variation in their
文摘In this work, ZnO nanorod arrays grown by an electrochemical deposition method are investigated. The crucial parameters of length, diameter, and density of the nanorods are optimized over the synthesize process and nanorods growth time. Crystalline structure, morphologies, and optical properties of ZnO nanorod arrays are studied by different techniques such as x-ray diffraction, scanning electron microscope, atomic force microscope, and UV-visible transmission spectra. The ZnO nanorod arrays are employed in an inverted bulk heterojunction organic solar cell of Poly （3-hexylthiophene）：[6- 6] Phenyl-（6） butyric acid methyl ester to introduce more surface contact between the electron transporter layer and the active layer. Our results show that the deposition time is a very important factor to achieve the aligned and uniform ZnO nanorods with suitable surface density which is required for effective infiltration of active area into the ZnO nanorod spacing and make a maximum interfacial surface contact for electron collection, as overgrowing causes nanorods to be too dense and thick and results in high resistance and lower visible light transmittance. By optimizing the thickness of the active layer on top of ZnO nanorods, an improved efficiency of 3.17% with a high FF beyond 60% was achieved.
文摘By shallow seismic prospecting, it is showed that the faults in the sea area near the Yangtze River mouth are mainly the NE and NW-trending faults. The main activity time of fault is Pliocene to Early Pleistocene, and the latest activity is up to Middle Pleistocene. The maximum of fault is generally several tens meters with the throw decreased upward. The dislocation near the bottom of Middle Pleistocene is 12~13 m. The average vertical dis-placement rate is on a level of 10-3 mm/a.
文摘In order to clear the activated area in electrostatic accelerator facilities,four accelerator facilities were selected and typical neutron emission experiments were performed.Neutron flux during operation and induced activity caused by charged particles on the accelerator and its surrounding area after irradiation were measured.Also the monitored neutron flux and calculated value by Monte Carlo calculation using PHITS code were compared.It was confirmed that the results between calculated data and measured data showed the good agreement with each other.Finally,it was concluded that we have to take care the activation of beam line and target.But,it is not necessary to treat accelerator tank,surrounding materials,and building concrete as radioactive materials in case of decommissioning.
文摘Microbiological and physical\|chemical characteristics of subtropical forest, grassland and cropfield soils from the karst areas of Southwest China were investigated. The study revealed that the conversion of natural forest to other forms of land would lead to a reduction in soil organic C(26.2%-35.3%), total N(37.2%-55.8%), total P(32.9%-43.6%), microbial biomass C(35.4%-49.1%), N(37.2%-55.8%), and P(25.8%-41.9%). Comparative analysis of microbial activity in terms of basal soil respiration showed maximum activity in forest soil and minimum in cropfield soil. Analysis of microbial metabolic respiratory activity indicated a relatively greater respiratory loss of CO\-2—C per unit microbial biomass in cropfield and grassland than in forest soil. Considering the importance of microbial components in soil, it is concluded that land use in different ways will lead to the reduction of biological stability of soil.
文摘In Burkina Faso, human activities are practiced in Nazinga Game Ranch (NGR) which is colonized by West African crocodiles Crocodylus suchus (Geoffroy Saint-Hilaire 1807) decades ago. This study which aims to estimate impact of anthropogenic activities on abundance of C. suchus has been conducted in NGR reservoirs. For data collection, C. suchus populations were counted morning, afternoon and night from October 2015 to May 2017 in 11 reservoirs. Binoculars were used for remote observations and spotlight was used by night. According to the size of the sites and its accessibility, direct observations were carried out on foot or by canoe. Every time we observed crocodiles, they were numbered and added information such as their size, their behavior, geographical coordinates and the type of habitat were collected. Human activities were noted after direct observations. The R software version 3.5.3 was used for data analysis. A total of 1849 crocodiles including hatchlings, juveniles, subadults and adults were counted in these 11 reservoirs of the NGR. They were more abundant in reservoirs than rivers with highest abundances in Akalon, Akwazena, Kalieboulou and Barka. Crocodile showed very high visibility at night their abundances showed important correlation with human activities and environmental factors such as roads, fishing, tourism, moon phases and “died crocodiles” and in NGR.
文摘The main purpose of this study is to identify the socio-economic implications of re-current flooding on women development in southern Ijaw Local Government Area. Generally, flooding may result in socio-economic, ecological and health problems. This study assumes that on flood days the movement of customers and sellers tends to be hindered, thus resulting in the retardation of transactions and the reduction of daily income earned. The study compared the situation of female traders with that of male traders. Both primary and secondary data were used in this study. Primary data were collected using an open-ended questionnaire. A total of 83 questionnaires were randomly distributed to members of four communities, which were selected through stratified random sampling procedures. Also 33 randomly selected women and men respectively, engaged in marketing activities from open and locked-up shops, were sampled to observe the level of their personal income (in Naira), from customers patronage during 3 flood days and 3 non-flood days. Other data and information were obtained through Key Informants Interview (KII), and observations. Hypotheses I and II were tested using Analysis of Variance (ANOVA) statistical model. Null hypothesis I (H<sub>0</sub>), which states that “There is no statistically significant difference in the income earned by men and women traders from marketing activities on flood days and non-flood days in Southern Ijaw Local Government Area, Bayelsa State”, is accepted (F-value: 3.8723939, P-value: 2.494E-05), whereas null hypothesis II (H<sub>0</sub>), which states that “There is no statistically significant difference in the income earned by women traders from marketing activities on flood and non-flood days in Southern Ijaw Local Government Area, Bayelsa State, is rejected (F-value: 2.524902, P-value: 0.030069). Thus while there is no significant difference in the earnings of male and female traders on flood and non-flood days, there are significant differences in sales earning among women traders on those days. Factors affecting trading income on flood and non-flood days include accessibility to business premises by customers, ability of male marketers to afford non-easily flooded business premises;and women traders with limited resources often have less suitably drained premises. Reduced total household income can detrimentally affect food affordability, availability, household nutrition, family health and wellbeing. Recommendations highlighting the roles of communities, government and stakeholders in flood management are proffered.
基金jointly supported by the National Natural Science Foundation of China (42106052)Shandong Provincial Natural Science Foundation (ZR2020QD070)the project of China Geological Survey (DD20190221)。
文摘Large amounts of gas hydrate are distributed in the northern slope of the South China Sea,which is a potential threat of methane leakage.Aerobic methane oxidation by methanotrophs,significant methane biotransformation that occurs in sediment surface and water column,can effectively reduce atmospheric emission of hydrate-decomposed methane.To identify active aerobic methanotrophs and their methane oxidation potential in sediments from the Shenhu Area in the South China Sea,multi-day enrichment incubations were conducted in this study.The results show that the methane oxidation rates in the studied sediments were 2.03‒2.36μmol/gdw/d,which were higher than those obtained by sediment incubations from other areas in marine ecosystems.Thus the authors suspect that the methane oxidation potential of methanotrophs was relatively higher in sediments from the Shenhu Area.After the incubations family Methylococcaea(type I methanotrophs)mainly consisted of genus Methylobacter and Methylococcaea_Other were predominant with an increased proportion of 70.3%,whereas Methylocaldum decreased simultaneously in the incubated sediments.Collectively,this study may help to gain a better understanding of the methane biotransformation in the Shenhu Area.
